Improvement in draft-regulating dampers



UNITED STATES PATENT QEEIcE.

ROYAL STYLES DUNHAM, OF COLDVATER, MICHIGAN.

IMPROVEMENT IN DRAFTd-REGULATING DAMPERS.

Specification forming part of Letters Patent No. l 52,089, dated June16,1874; application [iled September 14, 1871.

To all whom t may concern Beit known that I, ROYAL STYLES DUN- HAM, ofthe city of Coldwater, in the county of Branch and State of Michigan,have i11- venteda new and valuable Improvement in Draft-RegulatingDamper for controlling the draft of the fire under or.for steam-boilers;and I do hereby declare that the following is a full, clear, and exactdescription of the construction and operation of thc same, referencebeing had to the annexed drawings making a part of this specification,and to the letters and figures of reference marked thereon.

Figure 1 of the drawings is a representation of a vertical section of myinvention. Fig. 2 is a detail.

This invention has relation to dampers for the lines of steam-boilerfurnaces; andthe novelty consists in the herein-described method ofestablishing a connection between the safety-valve pipe and the damper,whereby the latter may be operated automatically by the force of thesteam escaping' through the safety-valve. The object of this inventionis the adapting of the heat to the condition of the steam, so as to keepup an equal pressure and prevent the waste of fuel.

Referring to the accompanying drawings illustrating this invention, Arepresents a steamboiler; B, the furnace; C, the draft-due leading fromthe interior of the latter; C', the safety-valve tube, within the firstsection of which is located the safety-valve D, of which E is the leverand E' the weight. F represents the damper pivoted within the iiue C,and provided with a crank-arm, f. Gr indicates a valve or piston withinthe safety-valve pipe, above the position of the safety-valve, but insuch relation to it that the escaping steam may act on said piston anddrive it upward. H represents a lever-arm, which is pivoted at one endto the rod g of the piston G, and at the other end to an arm, 7L, whichis coupled to the crank-armf on the dampershaft. I represents a-weighthung on the lever H, and capable of adjustment, so as to adapt thepiston to work at dierent pressures of steam. The steam-escape pipe iscontinued above the lever H by means of the curved sections'I, betweenwhich the lever extends. The lever H is pivoted to any conveuient partof the engine-frame or surroundings.

XVhen the fire is being kindled and just started, the damper is supposedto be fully opened to allow free draft at the same time the safety-valveis closed, and the piston down. When the steam generates and attains theproper pressure to which the weights E and I are adapted, the valve Dopens, and,

allowing the escape-steam to act on the pis-- ton, raises the latter,and through the medium of the levers H h and crank-arm f closes thedamper and shuts oft' the draft, thus establishing an intimatecombination between the damper and the safety-valve. A simple, butperhaps less effectual, method of producing the described effect may beprovided by simply entending the rlever of the vsafety-,valve of twowitnesses.

ROYAL S. DUNHAM. Witnesses:

' DAVID N. GREEN,

J E. PERRY.

